Process for producing openwork structures



Nov. 19, 1929. R. A. LEWIS. ET AL.

PROCESS FOR PRODUCING OPEN WORK STRUCTURES Filed Jan. 28. 1928 2 s uts-sum 1 INVENTORS d. Leww avid;

and I ORNEY;

Nov. 19, 1929. R. A. LEWIS El AL PROCESS FOR PRODUCING OPEN WORK STRUCTURES Filed Jan. 28. 1928- -2 stints-shoe; 2

INVENTOl: S 10m 7220;

} ATTORNEY Patented Nov. 19, 1929 UNITED STATES PATENT OFFICE BOY A. LEWIS AND DAVID L. EYNON, 0F BETHLEHEM, PENNSYLVANIA, ASSIGNORS TO BETHLEHEM STEEL COMPANY PROCESS FOR PRODUCING OPENWORK STRUCTURES Application filed January 28, 1928. Serial No; 250,134.

Our invention relates to those processes for the manufacture of open work metal structures wherein the cuts or openings are made in a metal blank and by expanding or working in some way, the open work is developed in the blank. In these various processes the steps of opening up the metal fre uently produce weakened portions at the p aces where the strands or latticed elements are joined, both to each other and to the remaining structure. The principal purpose of our invention is to avoid this weakening effect.

Broadly therefore our invention consists of steps for so working the blanks as to provide for an excess of metal in those portions which are normally weak so that upon the expanding step the excess of metal prevents the usual weakening.

Referring to the drawings, which illustrate two embodiments of the invention applied to the manufacture of flanged beams, having a latticed web;

Fig. 1 is a plan View largely diagrammatic in character of an apparatus for producing an open work beam;

Fig. 2 is a plan view on a somewhat larger scale than that given in Fig.1, of the central portions of the cutters used upon the rolls;

Fig. 3 is a similar plan View of an end portion of such a cutter;

Figs. 4 and 5 are cross sections taken on the lines IVIV and VV of Figs. 2 and 3 respectively; a

Fig. 6 is a cross section, on a reduced scale, of a blank before being expanded;

Fig. 7 is a cross section of the apparatus ind blank taken on the lines VII-VII of ig. 8 is a front end elevation of the guides;

Fig. 9 is a plan view, similar to that of Fig. 1, but showing a different type of cutter on the rolls for producing the strands in the web of the blank; and

Figs. 10 and 11 are plan views of the beams proclluced by the rolls of Figs. 1 and 9 respective Tlie beam (1 of Fig. 10 comprises flanges 10 and web 11 made up of latticed strands 12 which are joined to each other and to the web portions 13, adjacent to the flanges, by bonds 14 and 1 1 respectively. This beam is producedas follows: Blank I), having flanges 10', and web 11, is first passed between the web engaging rolls 15 and 16 which rolls are provided with the circumferential slitting elements or cutters 17 and 17, engaging the web at the central portions thereof and at the outer portions, respectively. The cutting elements 17 and 17 on eachroll are arranged to produce parallel cuts on the web, all running lengthwise thereof, and :in staggered relationship, centrally and marginally of the web; that is to say,'the cuts of the central parts of the web are staggered with reference to the cuts adjacent the flanges. 'The cutting elements on one roll are, set opposite to corresponding elements on the other roll. As is clear, especially from Figs. 4 and 5, these cutting or slitting elements'are wedge shaped in cross section. As a consequence, when the blank is passed between the rolls the web will not only be cut but will be simultaneously reduced, the metal of the forming strands being displaced between the wedge shaped elements 17 and 17 to elongate such strands.

Arranged to engage the inner flanged 'sur- What has just been outlined is not new with us. We will now point out those features which involve our contribution to the art. As

is clear from Figs. 1, 2, 3, 4; and 5, the cutters 17 and 17 while wedge like or triangular in cross section, throughout their length, taper OK at and near each end 20; the cutting ele-- ments 17, that is the central cutting elements also taper off toward thecentral portions 21 Naturally the result of this tapering off is that, as clearly indicated in Figs. 4 and 5, the cutters, at these places, have much'less wedging action, the angle-atthe cutting edge beiii) ing much more acute. Consequently when the blank is passed between the rolls, this difference in wedging action will result in the strands being appreciably less reduced in cross sectional area where engaged by the end and central portions of the cutters 17 and 17, than in the remaining portions. As the narrowed wedge portions 20 and 21, that is those portions of the cutters at the middle and at the ends, will engage the web material to cut it to form those portions of the strand which are adjacent to the bonds, the natural result will be that the strands are less reduced in cross section in those portions than through out the greater part of their length.

An advantageous result is thus secured, the

portions of the strandsnear the bonds being of greater cross sectional area, will naturally resist the usual weakening effects produced at these points during the expandingro r equivalent operation.

The same elfect, that is the presence of a greater cross sectional area of the strands in the vicinity of and at the junction ofsuch strands with the bonds, may be secured by other methods. For example, the beam of Fig. 11 has latticed elements with the portions 26 and 26, adjacent the bonds 27 and 27, of greater cross sectional area than the remainder of such strands. These beams are prepared by rolling and expanding in a manner similar to that of Fig. 1, but with the rolls provided with cutters such as are set forth in Fig. 9. These cutters are wedge shaped,

9:; like those'in the rolls of Fig. 1 but they do not taper appreciably at the ends and central portions as in the first described form, Here the greater cross sectional area of the strands near the bonds is produced by having those portions of the two cutters which engage the two sides of the strand at a greater distance apart in the regions adjacent the bonds than in the remaining regions.

Referring to Fig. 9, the rolls and guides correspond in every respect to those of the form previously described except as regards the rolls 28. The central cutting elements 29 are circumferential, being shaped substantially the same as the cutters of thefirst clescribed form except that there is no tapering oii in the Wedge like cross section at the middle and end portions. The marginal cutters 3'0,that is the cutt'erson each sideof the roll periphery, which engage the web in the portions adjacent the flanges, are parallel to the central cutters 29 throughout most of their length but diverge therefrom at the end and interior regions 31 and 32 respectively. Obviously when a blank is passed between the ions, as in the preceding example, the resulting strands produced will be wider in the region adjacent the bonds than in the remaining portions.

it is clear that this method may be applicable to any open work metal. Also, it is obvious, that, while the process here outlined involves the reduction of the web material, the principle of our invention is applicable to processes wherein a web or other part is slitted Without any accompanying or subsequent reduction of this slitted part but is merely expanded as by any suitable separating operation.

In referring to the operation of slitting to form strands,the actual cutting operation, in some cases, may not completely separate the metal, in such casebeing more truly deep ,scorings than actual slitting. Clearly it is in'imaterial'so far asthe essential invention is concerned just how complete the cutting is of the metal. Accordingly in the claimswe use the expression slitting in the broader sense.

It is of course understood that the ordinary rolling and other manipulating operations,

choice of materials, temperatures of working, and so forth may be employed, as well as any desired variation therefrom. thingis the preparation of the strands to be of greater dimensions adjacent the bonds than elsewhere.

. Having described our invention what we desireto claim protection on is as follows:

1. In a process of making an open work structure, the steps of slitting'a blank to form strands connected by bonds, the cross sec- 'tional area of each strand being greater where it joins a bond, and expanding the blank to "form anopen work structure. a

2. In a process of'making an open work metal structure, the steps of slitting a blank :to form strands connected by bonds, the cross- ;sectional dimensions of each strand increasing near and at the points of junction with the bonds, and expanding the blank to fori an open work structure.

3.111 a process of making an open work metal structure, the steps of slitting to form strands connected by bonds and simultaneously reducing the material of the strands to elongate them, the reduction being less in the proximity of the bonds, and expanding the blank to produce an open work.

In testimonywhereof we hereunto aflix our signatures.

ROY A. LEWVIS. DAVID L. EYNON.

While these two illustrationsshow the application" of the invention to flange beams The essential 

